A team of international researchers collected data from Comet Wirtanen which was nicknamed the “Christmas comet” after it passed close to Earth in December 2018, near enough for people to catch a glimpse. Scientists observed the bright green comet and collected data using American space agency NASA’s Stratospheric Observatory for Infrared Astronomy (SOFIA) – the world’s largest airborne observatory which operates out of a Boeing 747. The groundbreaking findings were published in an eight-page report in the journal Astronomy and Astrophysics Letters on May 20.
What they found was a type of water similar to what we have on our planet which they say could mean comets played a part in bringing up to 70 percent of the water to Earth.
Darek Lis, the study’s lead author, said in a statement: “We have identified a vast reservoir of Earth-like water in the outer reaches of the solar system.
“Water was crucial for the development of life as we know it.
“We not only want to understand how Earth’s water was delivered, but also if this process could work in other planetary systems.”
But there is only limited evidence to suggest the type of water present on our planet is the same kind found in distant comets.
H2O, the water in our seas, consists of two hydrogen atoms, containing one proton and zero neutrons, and one oxygen atom.
Another type of water known as “heavy water” has a similar structure, but the hydrogen atom contains one proton and one neutron.
Known as deuterium, it is a less common form of water found on Earth.
When a comet approaches the sun it heats up and releases water from ice on its surface – forming a vaporous atmosphere.
Astronomers zoned in on the ratio of the two types of water in an effort to establish the origin of the liquid.
The D/H ratio in comets usually varies between 1 to 3 times more than that of Earth’s oceans.
However, the team claims to have found D/H ratios in three comets – 103P/Hartley, 45P/H-M-P and the so-called Christmas comet – which are similar to the ratio of terrestrial water.
In particular, the Christmas comet which was analysed when it came close to Earth, was found to have the exact same D/H ratio as water in our oceans.
Up until now research has shown comets’ water differs from that on our planet.